CN101860762A - System for converting RGB three colors to RGBW four colors - Google Patents

Abstract

The invention provides a system for converting RGB three colors (red, green and blue) to RGBW four colors (red, green, blue and white). The system comprises an input unit, a processing unit and a control unit, wherein the input unit is used for inputting the gray value of R, G and B; the processing unit is used for converting the gray value of R, G and B received by the input unit into the gray value of R, G, B and W and outputting the gray value; and the control unit is used for receiving the output value of the processing unit and controlling the execution of LED equipment according to the output value. The system for converting three colors to four colors ensures the complete consistency of the saturation and the brightness of mixed light, has low power and saves energy, and additionally, the service life of the system is prolonged because the heat productivity of hardware is low.

Description

A kind of RGB three looks change the system of RGBW four looks

[technical field]

The present invention relates to a kind of color space conversion system, relate in particular to the system that a kind of RGB three looks change RGBW four looks.

[background technology]

In the LED application facet, because the mixed light efficient of RGB trichromatic system is very low, the white light color rendering of mixing out is very poor, so gradually adopting RGBW four colour systems to unite, people replace the RGB trichromatic system, white light LEDs is the light efficiency height not only, and color rendering is also higher relatively, and the RGBW system can realize the function that the RGB system is realized fully in addition.The present RGBW four colour systems system increase white lights that adopt come the RGB mixed light is compensated more, though this method is simple and the brightness that can improve whole mixed light, but, increasing white light simply and can allow original RGB mixed light unmanageable deviation occur, the inconsistent deviation of this species saturation and brightness many times is difficult to accept, in addition, the system power of this mixed light mode is higher, and the hardware caloric value is bigger, causes hardware longevity shorter, and this method is not considered actual power saving.

[summary of the invention]

At the problems referred to above, the invention provides the system that a kind of RGB three looks change RGBW four looks, it is inconsistent to have solved in the prior art saturation and the brightness of mixed light, and the higher not problem of energy saving of power.

The invention provides a kind of RGB (RGB) three looks changes the system of RGBW (red, green, blue and white) four looks, and described system comprises input unit, processing unit and control unit;

Described input unit is used to import the gray value of R, G, B;

Described processing unit is used for:

To be the gray value of R, G, B, W from R, G, the B grayvalue transition of input unit input,

Judge whether this group gray value all is not less than zero,

If whether the gray value of then judging W is greater than the highest tonal gradation: if then change this group gray value and output; Otherwise, export the effective value of this group gray value;

Otherwise, then carry out R, G again, the B grayvalue transition is the gray value of R, G, B, W, until output corresponding grey scale value;

Described control unit is used to receive the output valve of processing unit, and carries out according to output valve control LED equipment,

Wherein, described effective value is meant the value in each gray value span.

As a further improvement on the present invention, described processing unit comprises central processor unit, data determining unit and data output unit, and it is the gray value of R, G, B, W that described central processor unit is used for R, G, B grayvalue transition; Data determining unit is used for data converted is carried out analyzing and processing; The data output unit is used for data processed is exported.

As a further improvement on the present invention, described input unit is the keyboard that is connected with processing unit.

As a further improvement on the present invention, described processing unit determines that the step of output valve comprises:

Receive the gray value of R, G, B;

The gray scale output valve that makes first color is 0, calculates the gray value of R, G, B, other colors of W, draws first group of R, G, B, W gray value;

Judge that whether first group of R, G, B, W gray value are all more than or equal to 0, if, whether the gray value of then judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light is the highest tonal gradation, the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after the output conversion; Otherwise, export the effective value of this group gray value;

Otherwise the gray scale output valve that makes second color is 0, calculates the gray value of R, G, B, other colors of W, draws second group of R, G, B, W gray value;

Judge that second group of R, G, B, W gray value are all more than or equal to 0, if, whether the gray value of then judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light is the highest tonal gradation, the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after the output conversion; Otherwise, export the effective value of this group gray value;

Otherwise, the gray scale output valve that makes the 3rd color is 0, calculate the gray value of R, G, B, other colors of W, whether the gray value of judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light be the highest tonal gradation, and the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after output is changed; Otherwise, export the effective value of this group gray value;

Wherein, the arbitrary color of R, G, B in the first color showing RGBW system; Arbitrary color among the second color showing R, G, the B except that first color; Another kind of color among the 3rd color showing R, G, the B except that first color and second color.

As a further improvement on the present invention, the span of described input value r, g, b be 0 to

Wherein, r represents the tonal gradation of R; G represents the tonal gradation of G; B represents the tonal gradation of B; M represents the maximum of tonal gradation.

As a further improvement on the present invention, calculating the parameter that R, G, the gray value of B, W need use comprises:

The chromaticity coordinate of R (x1, y1); The chromaticity coordinate of G (x2, y2); The chromaticity coordinate of B (x3, y3); The chromaticity coordinate of W (x4, y4);

$\mathrm{Kr}=\frac{\mathrm{Fr}}{y1},$ $\mathrm{Kg}=\frac{\mathrm{Fg}}{y2},$ $\mathrm{Kb}=\frac{\mathrm{Fb}}{y3},$ $\mathrm{Kw}=\frac{\mathrm{Fw}}{y4},$

Fr represents the luminous flux of R when maximum tonal gradation m; Fg represents the luminous flux of G when maximum tonal gradation m; Fb represents the luminous flux of B when maximum tonal gradation m; Fw represents the luminous flux of W when maximum tonal gradation m.

As a further improvement on the present invention, calculate the gray scale output valve that makes R in the described output valve and be 0 computing formula and be,

$\left\{\begin{array}{c}r1=0\\ g1=\frac{-(x1-x3)(y3-y4)+(x3-x4)(y1-y3)}{-(x2-x3)(y3-y4)+(x3-x4)(y2-y3)}\×\frac{\mathrm{Kr}}{\mathrm{Kg}}\×r+g\\ b1=\frac{-(x1-x2)(y2-y4)+(x2-x4)(y1-y2)}{(x2-x3)(y2-y4)-(x2-x4)(y2-y3)}\×\frac{\mathrm{Kr}}{\mathrm{Kb}}\×r+b\\ w1=\frac{-(x1-x2)(y2-y3)+(x2-x3)(y1-y2)}{(x2-x4)(y2-y3)-(x2-x3)(y2-y4)}\×\frac{\mathrm{Kr}}{\mathrm{Kw}}\×r\end{array}\right.---\left(1\right)$

The gray scale output valve that makes G is that 0 computing formula is,

$\left\{\begin{array}{c}r1=\frac{-(x2-x3)(y3-y4)+(x3-x4)(y2-y3)}{-(x1-x3)(y3-y4)+(x3-x4)(y1-y3)}\×\frac{\mathrm{Kg}}{\mathrm{Kr}}\×g+r\\ g1=0\\ b1=\frac{(x1-x2)(y1-y4)-(x1-x4)(y1-y2)}{(x1-x3)(y1-y4)-(x1-x4)(y1-y3)}\×\frac{\mathrm{Kg}}{\mathrm{Kb}}\×g+b\\ w1=\frac{(x1-x2)(y1-y3)-(x1-x3)(y1-y2)}{(x1-x4)(y1-y3)-(x1-x3)(y1-y4)}\×\frac{\mathrm{Kg}}{\mathrm{Kw}}\×g\end{array}\right.---\left(2\right)$

The gray scale output valve that makes B is that 0 computing formula is,

$\left\{\begin{array}{c}r1=\frac{(x2-x3)(y2-y4)-(x2-x4)(y2-y3)}{-(x1-x2)(y2-y4)+(x2-x4)(y1-y2)}\×\frac{\mathrm{Kb}}{\mathrm{Kr}}\×b+r\\ g1=\frac{(x1-x3)(y1-y4)-(x1-x4)(y1-y3)}{(x1-x2)(y1-y4)-(x1-x4)(y1-y2)}\×\frac{\mathrm{Kb}}{\mathrm{Kg}}\×b+g\\ b1=0\\ w1=\frac{(x1-x3)(y1-y2)-(x1-x2)(y1-y3)}{(x1-x4)(y1-y2)-(x1-x2)(y1-y4)}\×\frac{\mathrm{Kb}}{\mathrm{Kw}}\×b\end{array}\right.---\left(3\right).$

As a further improvement on the present invention, when the gray scale output valve of R was 0, whether the gray value of judging W comprised greater than the step of high tonal gradation:

If w1≤m, output r1=0, g1=min (g1, m), b1=min (b1, m), w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a2*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}},$

$g1=\frac{a2*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a1*g1*m}{w1*\mathrm{Fw}}+g1,$

$b1=\frac{a2*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a1*b1*m}{w1*\mathrm{Fw}}+b1.$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

When the gray scale output valve of G was 0, whether the gray value of judging W comprised greater than the step of high tonal gradation:

If w1≤m, and output r1=min (r1, m), g1=0, b1=min (b1, m), w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a4*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a3*r1*m}{w1*\mathrm{Fw}}+r1,$

$g1=\frac{a4*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}},$

$b1=\frac{a4*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a3*b1*m}{w1*\mathrm{Fw}}+b1$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

When the gray scale output valve of B was 0, whether the gray value of judging W comprised greater than the step of high tonal gradation:

If w1≤m, and output r1=min (r1, m), g1=min (g1, m), b1=0, w1=w1;

If w1＞m,

Order Formula below calculating

$r1=\frac{a6*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a5*r1*m}{w1*\mathrm{Fw}}+r1,$

$g1=\frac{a6*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a5*g1*m}{w1*\mathrm{Fw}}+g1,$

$b1=\frac{a6*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}.$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

The invention has the beneficial effects as follows: 1, the chromaticity coordinates of mixed light and luminous flux are in full accord, have guaranteed that the saturation of mixed light and brightness are in full accord; 2, the system power after the conversion has been realized energy-conservation effect less than RGB trichromatic system power; 3, because power is little, the caloric value of hardware is less, has prolonged the useful life of hardware device.

[description of drawings]

Fig. 1 is the flow chart that three looks of the present invention change embodiment one in the four colour systems system;

Fig. 2 is RGB three look gamut map of the present invention;

Fig. 3 is RGBW four look gamut map of the present invention.

[embodiment]

In order to make purpose of the present invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.

Specific embodiment one

As shown in Figures 1 to 3, the invention provides the system that a kind of RGB (RGB) three looks change RGBW (red, green, blue and white) four looks, described system comprises input unit, processing unit and control unit;

Described input unit is the keyboard that links to each other with processing unit, is used to import the gray value of R, G, B;

Described processing unit is used for:

To be the gray value of R, G, B, W from R, G, the B grayvalue transition of input unit input,

Judge whether this group gray value all is not less than zero,

If whether the gray value of then judging W is greater than the highest tonal gradation: if then change this group gray value and output; Otherwise, export the effective value of this group gray value; Described effective value is meant the value in each gray value span;

Otherwise, then carry out R, G again, the B grayvalue transition is the gray value of R, G, B, W, until output corresponding grey scale value;

Described control unit is used to receive the output valve of processing unit, and carries out according to output valve control LED equipment.

Described processing unit comprises central processor unit, data determining unit and data output unit, and it is the gray value of R, G, B, W that described central processor unit is used for R, G, B grayvalue transition; Data determining unit is used for data converted is carried out analyzing and processing; The data output unit is used for data processed is exported.

Described processing unit determines that the step of output valve comprises:

Receive the gray value of R, G, B;

The gray scale output valve that makes first color is 0, calculates the gray value of R, G, B, other colors of W, draws first group of R, G, B, W gray value;

Judge that whether first group of R, G, B, W gray value are all more than or equal to 0, if, whether the gray value of then judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light is the highest tonal gradation, the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after the output conversion; Otherwise, export the effective value of this group gray value;

Otherwise the gray scale output valve that makes second color is 0, calculates the gray value of R, G, B, other colors of W, draws second group of R, G, B, W gray value;

Judge that second group of R, G, B, W gray value are all more than or equal to 0, if, whether the gray value of then judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light is the highest tonal gradation, the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after the output conversion; Otherwise, export the effective value of this group gray value;

Otherwise, the gray scale output valve that makes the 3rd color is 0, calculate the gray value of R, G, B, other colors of W, whether the gray value of judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light be the highest tonal gradation, and the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after output is changed; Otherwise, export the effective value of this group gray value;

Wherein, the arbitrary color of R, G, B in the first color showing RGBW system; Arbitrary color among the second color showing R, G, the B except that first color; Another kind of color among the 3rd color showing R, G, the B except that first color and second color.

The span of described input value r, g, b is 0 to m,

Wherein, r represents the tonal gradation of R; G represents the tonal gradation of G; B represents the tonal gradation of B; M represents the maximum of tonal gradation.

The parameter that calculating R, G, the gray value of B, W need use comprises:

The chromaticity coordinate of R (x1, y1); The chromaticity coordinate of G (x2, y2); The chromaticity coordinate of B (x3, y3); The chromaticity coordinate of W (x4, y4);

$\mathrm{Kr}=\frac{\mathrm{Fr}}{y1},$ $\mathrm{Kg}=\frac{\mathrm{Fg}}{y2},$ $\mathrm{Kb}=\frac{\mathrm{Fb}}{y3},$ $\mathrm{Kw}=\frac{\mathrm{Fw}}{y4},$

Fr represents the luminous flux of R when maximum tonal gradation m; Fg represents the luminous flux of G when maximum tonal gradation m; Fb represents the luminous flux of B when maximum tonal gradation m; Fw represents the luminous flux of W when maximum tonal gradation m.

Calculate in the described output valve, the gray scale output valve that makes R is that 0 computing formula is,

$\left\{\begin{array}{c}r1=0\\ g1=\frac{-(x1-x3)(y3-y4)+(x3-x4)(y1-y3)}{-(x2-x3)(y3-y4)+(x3-x4)(y2-y3)}\×\frac{\mathrm{Kr}}{\mathrm{Kg}}\×r+g\\ b1=\frac{-(x1-x2)(y2-y4)+(x2-x4)(y1-y2)}{(x2-x3)(y2-y4)-(x2-x4)(y2-y3)}\×\frac{\mathrm{Kr}}{\mathrm{Kb}}\×r+b\\ w1=\frac{-(x1-x2)(y2-y3)+(x2-x3)(y1-y2)}{(x2-x4)(y2-y3)-(x2-x3)(y2-y4)}\×\frac{\mathrm{Kr}}{\mathrm{Kw}}\×r\end{array}\right.---\left(1\right)$

The gray scale output valve that makes G is that 0 computing formula is,

$\left\{\begin{array}{c}r1=\frac{-(x2-x3)(y3-y4)+(x3-x4)(y2-y3)}{-(x1-x3)(y3-y4)+(x3-x4)(y1-y3)}\×\frac{\mathrm{Kg}}{\mathrm{Kr}}\×g+r\\ g1=0\\ b1=\frac{(x1-x2)(y1-y4)-(x1-x4)(y1-y2)}{(x1-x3)(y1-y4)-(x1-x4)(y1-y3)}\×\frac{\mathrm{Kg}}{\mathrm{Kb}}\×g+b\\ w1=\frac{(x1-x2)(y1-y3)-(x1-x3)(y1-y2)}{(x1-x4)(y1-y3)-(x1-x3)(y1-y4)}\×\frac{\mathrm{Kg}}{\mathrm{Kw}}\×g\end{array}\right.---\left(2\right)$

The gray scale output valve that makes B is that 0 computing formula is,

$\left\{\begin{array}{c}r1=\frac{(x2-x3)(y2-y4)-(x2-x4)(y2-y3)}{-(x1-x2)(y2-y4)+(x2-x4)(y1-y2)}\×\frac{\mathrm{Kb}}{\mathrm{Kr}}\×b+r\\ g1=\frac{(x1-x3)(y1-y4)-(x1-x4)(y1-y3)}{(x1-x2)(y1-y4)-(x1-x4)(y1-y2)}\×\frac{\mathrm{Kb}}{\mathrm{Kg}}\×b+g\\ b1=0\\ w1=\frac{(x1-x3)(y1-y2)-(x1-x2)(y1-y3)}{(x1-x4)(y1-y2)-(x1-x2)(y1-y4)}\×\frac{\mathrm{Kb}}{\mathrm{Kw}}\×b\end{array}\right.---\left(3\right)$

Described processing unit to R, G, B respectively the order of zero setting be R, G, B, its detailed process process is as follows:

The gray scale output valve that makes R is 0, calculates one group of R, G, B, W value with formula (1);

Judge that this class value whether all more than or equal to zero, if not, then enters the gray value zero-setting operation of G; Otherwise, make the following judgment:

Whether the gray value of judging W comprises greater than the step of high tonal gradation:

If w1≤m, output r1=0, g1=min (g1, m), b1=min (b1, m), w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a2*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}},$

$g1=\frac{a2*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a1*g1*m}{w1*\mathrm{Fw}}+g1,$

$b1=\frac{a2*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a1*b1*m}{w1*\mathrm{Fw}}+b1.$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

The gray value zero-setting operation of G:

The gray value that makes G is zero, calculates one group of R, G, B, W value with formula (2);

Judge that this class value whether all more than or equal to zero, if not, then enters the gray value zero-setting operation of B; Otherwise, make the following judgment:

If w1≤m, and output r1=min (r1, m), g1=0, b1=min (b1, m), w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a4*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a3*r1*m}{w1*\mathrm{Fw}}+r1,$

$g1=\frac{a4*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}},$

$b1=\frac{a4*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a3*b1*m}{w1*\mathrm{Fw}}+b1$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.The gray value zero-setting operation of B:

The gray value that makes B is zero, calculates one group of R, G, B, W value with formula (3);

Whether the gray value of judging W is greater than the highest tonal gradation:

If w1≤m, and output r1=min (r1, m), g1=min (g1, m), b1=0, w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a6*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a5*r1*m}{w1*\mathrm{Fw}}+r1,$

$g1=\frac{a6*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a5*g1*m}{w1*\mathrm{Fw}}+g1,$

$b1=\frac{a6*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}.$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

After described control unit receives the output valve of processing unit, carry out concrete operations according to described output valve control LED equipment;

Specific embodiment two

Present embodiment is with respect to the difference of specific embodiment one:

Described processing unit can also be R, B, G to the order of R, G, the zero setting of B difference.

Specific embodiment three

Present embodiment is with respect to specific embodiment one and two difference:

Described processing unit can also be G, R, B to the order of R, G, the zero setting of B difference.

Specific embodiment four

Present embodiment is with respect to the difference of specific embodiment one to three:

Described processing unit can also be G, B, R to the order of R, G, the zero setting of B difference.

Specific embodiment five

Present embodiment is with respect to the difference of specific embodiment one to four:

Described processing unit can also be B, R, G to the order of R, G, the zero setting of B difference.

Specific embodiment six

Present embodiment is with respect to the difference of specific embodiment one to five:

Described processing unit can also be B, G, R to the order of R, G, the zero setting of B difference.

Above content be in conjunction with concrete preferred implementation to further describing that the present invention did, can not assert that concrete enforcement of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.

Claims (10)

1. a RGB (RGB) three looks change the system of RGBW (red, green, blue and white) four looks, and it is characterized in that: described system comprises input unit, processing unit and control unit;

Described input unit is used to import the gray value of R, G, B;

Described processing unit is used for:

To be the gray value of R, G, B, W from R, G, the B grayvalue transition of input unit input, judge whether this group gray value all is not less than zero,

If whether the gray value of then judging W is greater than the highest tonal gradation: if then change this group gray value and output; Otherwise, export the effective value of this group gray value;

Otherwise, then carry out R, G again, the B grayvalue transition is the gray value of R, G, B, W, until output corresponding grey scale value;

Described control unit is used to receive the output valve of processing unit, and carries out according to output valve control LED equipment,

Wherein, described effective value is meant the value in each gray value span.

2. a kind of RGB three looks according to claim 1 change the system of RGBW four looks, it is characterized in that: described processing unit comprises central processor unit, data determining unit and data output unit, and it is the gray value of R, G, B, W that described central processor unit is used for R, G, B grayvalue transition; Data determining unit is used for data converted is carried out analyzing and processing; The data output unit is used for data processed is exported.

3. a kind of RGB three looks according to claim 1 change the system of RGBW four looks, and it is characterized in that: described input unit is the keyboard that is connected with processing unit.

4. a kind of RGB three looks according to claim 1 change the system of RGBW four looks, and it is characterized in that: described processing unit determines that the step of output valve comprises:

Receive the gray value of R, G, B;

The gray scale output valve that makes first color is 0, calculates the gray value of R, G, B, other colors of W, draws first group of R, G, B, W gray value;

Judge that whether first group of R, G, B, W gray value are all more than or equal to 0, if, whether the gray value of then judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light is the highest tonal gradation, the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after the output conversion; Otherwise, export the effective value of this group gray value;

Otherwise the gray scale output valve that makes second color is 0, calculates the gray value of R, G, B, other colors of W, draws second group of R, G, B, W gray value;

Judge that second group of R, G, B, W gray value are all more than or equal to 0, if, whether the gray value of then judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light is the highest tonal gradation, the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after the output conversion; Otherwise, export the effective value of this group gray value;

Otherwise, the gray scale output valve that makes the 3rd color is 0, calculate the gray value of R, G, B, other colors of W, whether the gray value of judging W is greater than the highest tonal gradation: if, then should organize gray value according to the ratio of this moment reduces in proportion simultaneously, and the gray value that guarantees white light be the highest tonal gradation, and the gray value that increases R, G, B then is to replenish the loss of luminous flux, R, G, B, W gray value after output is changed; Otherwise, export the effective value of this group gray value;

Wherein, the arbitrary color of R, G, B in the first color showing RGBW system; Arbitrary color among the second color showing R, G, the B except that first color; Another kind of color among the 3rd color showing R, G, the B except that first color and second color.

5. a kind of RGB three looks according to claim 4 change the system of RGBW four looks, and it is characterized in that: the span of described input value r, g, b is 0 to m,

Wherein, r represents the tonal gradation of R; G represents the tonal gradation of G; B represents the tonal gradation of B; M represents the maximum of tonal gradation.

6. a kind of RGB three looks according to claim 4 change the system of RGBW four looks, it is characterized in that: the parameter that calculating R, G, the gray value of B, W need use comprises:

The chromaticity coordinate of R (x1, y1); The chromaticity coordinate of G (x2, y2); The chromaticity coordinate of B (x3, y3); The chromaticity coordinate of W (x4, y4);

$\mathrm{Kr}=\frac{\mathrm{Fr}}{y1},$ $\mathrm{Kg}=\frac{\mathrm{Fg}}{y2},$ $\mathrm{Kb}=\frac{\mathrm{Fb}}{y3},$ $\mathrm{Kw}=\frac{\mathrm{Fw}}{y4},$

Fr represents the luminous flux of R when maximum tonal gradation m; Fg represents the luminous flux of G when maximum tonal gradation m; Fb represents the luminous flux of B when maximum tonal gradation m; Fw represents the luminous flux of W when maximum tonal gradation m.

7. a kind of RGB three looks according to claim 4 change the system of RGBW four looks, it is characterized in that: calculating the gray scale output valve that makes R in the described output valve and be 0 computing formula is,

$\left\{\begin{array}{c}r1=0\\ g1=\frac{-(x1-x3)(y3-y4)+(x3-x4)(y1-y3)}{-(x2-x3)(y3-y4)+(x3-x4)(y2-y3)}\×\frac{\mathrm{Kr}}{\mathrm{Kg}}\×r+g\\ b1=\frac{-(x1-x2)(y2-y4)+(x2-x4)(y1-y2)}{(x2-x3)(y2-y4)-(x2-x4)(y2-y3)}\×\frac{\mathrm{Kr}}{\mathrm{Kb}}\×r+b\\ w1=\frac{-(x1-x2)(y2-y3)+(x2-x3)(y1-y2)}{(x2-x4)(y2-y3)-(x2-x3)(y2-y4)}\×\frac{\mathrm{Kr}}{\mathrm{Kw}}\×r\end{array}\right.---\left(1\right)$

The gray scale output valve that makes G is that 0 computing formula is,

$\left\{\begin{array}{c}r1=\frac{-(x2-x3)(y3-y4)+(x3-x4)(y2-y3)}{-(x1-x3)(y3-y4)+(x3-x4)(y1-y3)}\×\frac{\mathrm{Kg}}{\mathrm{Kr}}\×g+r\\ g1=0\\ b1=\frac{(x1-x2)(y1-y4)-(x1-x4)(y1-y2)}{(x1-x3)(y1-y4)-(x1-x4)(y1-y3)}\×\frac{\mathrm{Kg}}{\mathrm{Kb}}\×g+b\\ w1=\frac{(x1-x2)(y1-y3)-(x1-x3)(y1-y2)}{(x1-x4)(y1-y3)-(x1-x3)(y1-y4)}\×\frac{\mathrm{Kg}}{\mathrm{Kw}}\×g\end{array}\right.---\left(2\right)$

The gray scale output valve that makes B is that 0 computing formula is,

$\left\{\begin{array}{c}r1=\frac{(x2-x3)(y2-y4)-(x2-x4)(y2-y3)}{-(x1-x2)(y2-y4)+(x2-x4)(y1-y2)}\×\frac{\mathrm{Kb}}{\mathrm{Kr}}\×b+r\\ g1=\frac{(x1-x3)(y1-y4)-(x1-x4)(y1-y3)}{(x1-x2)(y1-y4)-(x1-x4)(y1-y2)}\×\frac{\mathrm{Kb}}{\mathrm{Kg}}\×b+g\\ b1=0\\ w1=\frac{(x1-x3)(y1-y2)-(x1-x2)(y1-y3)}{(x1-x4)(y1-y2)-(x1-x2)(y1-y4)}\×\frac{\mathrm{Kb}}{\mathrm{Kw}}\×b\end{array}\right.---\left(3\right).$

8. a kind of RGB three looks according to claim 4 change the system of RGBW four looks, and it is characterized in that: the gray scale output valve of R is 0 o'clock, and whether the gray value of judging W comprises greater than the step of high tonal gradation:

If w1≤m, output r1=0, g1=min (g1, m), b1=min (b1, m), w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a2*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}},$

$g1=\frac{a2*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a1*g1*m}{w1*\mathrm{Fw}}+g1,$

$b1=\frac{a2*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a1*b1*m}{w1*\mathrm{Fw}}+b1.$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

9. a kind of RGB three looks according to claim 4 change the system of RGBW four looks, and it is characterized in that: the gray scale output valve of G is 0 o'clock, and whether the gray value of judging W comprises greater than the step of high tonal gradation:

If w1≤m, and output r1=min (r1, m), g1=0, b1=min (b1, m), w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a4*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a3*r1*m}{w1*\mathrm{Fw}}+r1,$

$g1=\frac{a4*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}},$

$b1=\frac{a4*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a3*b1*m}{w1*\mathrm{Fw}}+b1$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

10. a kind of RGB three looks according to claim 4 change the system of RGBW four looks, and it is characterized in that: the gray scale output valve of B is 0 o'clock, and whether the gray value of judging W comprises greater than the step of high tonal gradation:

If w1≤m, and output r1=min (r1, m), g1=min (g1, m), b1=0, w1=w1;

If w1＞m,

Order

Formula below calculating

$r1=\frac{a6*r*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a5*r1*m}{w1*\mathrm{Fw}}+r1,$

$g1=\frac{a6*g*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}-\frac{a5*g1*m}{w1*\mathrm{Fw}}+g1,$

$b1=\frac{a6*b*m}{r*\mathrm{Fr}+g*\mathrm{Fg}+b*\mathrm{Fb}}.$

Output r1=min (r1, m), g1=min (g1, m), b1=min (b1, m), w1=m.

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